Conventionally, as an ultrasonic atomizing unit for use in an ultrasonic atomizing device, a unit is known which has a structure in which an atomizing member including a piezoelectric vibrator and a vibrating plate mounted to the piezoelectric vibrator is elastically sandwiched and held by a casing through elastic members formed from an elastic material (e.g., see Patent Literature 1).
FIG. 5 is a cross-sectional view illustrating an example of the ultrasonic atomizing unit described in Patent Literature 1, and FIG. 6 is an exploded perspective view of the ultrasonic atomizing unit. The ultrasonic atomizing unit includes: an atomizing member 100 including a piezoelectric vibrator 101 having an opening 101a at a central part thereof and a vibrating plate 102 mounted to the piezoelectric vibrator 101; a pair of elastic members 103 that are arranged so as to extend along both surfaces, respectively, of the atomizing member 100; and a casing 104 as a holding member that accommodates the atomizing member 100 and the elastic members 103 therein.
The piezoelectric vibrator 101 is formed from a circular thin plate-shaped piezoelectric ceramic. When a high-frequency voltage is applied to electrodes 101b provided on the upper and lower surfaces of the piezoelectric vibrator 101, ultrasonic vibrations occur such that the piezoelectric vibrator 101 expands and contracts in a radial direction thereof. In addition, the vibrating plate 102 is formed from a circular thin plate-shaped metal, and is mounted to the lower surface of the piezoelectric vibrator 101 so as to cover the opening 101a of the piezoelectric vibrator 101. The vibrating plate 102 has a large number of micropores 102a formed in a portion thereof which faces the opening 101a. 
The pair of elastic members 103 are formed from annular flat plate-shaped rubbers, and are adhered to both surfaces, respectively, of the atomizing member 100 so as to be in surface contact therewith. In addition, the casing 104 has a hollow circular plate shape with an opening at a central part thereof, and elastically sandwiches and holds therein the atomizing member 100 through the pair of elastic members 103. The casing 104 is divided into two upper and lower portions that are separable from each other.
According to the above conventional ultrasonic atomizing unit, a high-frequency voltage is applied to the piezoelectric vibrator 101 to ultrasonically vibrate the piezoelectric vibrator 101 to ultrasonically vibrate the vibrating plate 102, whereby a liquid supplied to the micropore 102a portion of the vibrating plate 102 can be atomized and sprayed.
Patent Literature 1 also discloses an ultrasonic atomizing unit in which instead of the thin plate-shaped elastic members 103, a pair of first elastic members 105 having rubber band shapes and a pair of second elastic members 106 having outer diameters larger than those of the first elastic members 105 are used, and the elastic members 105 and the elastic members 106 are arranged so as to extend along outer peripheral edges and opening edges of both surfaces, respectively, of the atomizing member 100 (see FIG. 7).